Sulfonamides of high molecular weight alkyl-substituted benzene sulfonic acids and their preparation

ABSTRACT

POLYMETHYLENE-CONTAINING SULFONAMIDES OF ALKYL SUBSTITUTED BENZENE SULFINIC ACIDS WHOSE ALKYL-SUBSTITUENT HAS A MOLECULAR WEIGHT IN THE RANGE OF 400 TO 2800 ARE OIL SOLUBLE, IMPART THERMALLY STABLE DISPERSANCY TO OIL SOLUTIONS OF THE SULFONAMIDES. THE SULFONAMIDES ARE PREFERABLY POLYMETHYLENE--CONTAINING DIPRIMARY AMINES SUCH AS POLYAZALKYLENE DIAMINE, POLYMETHYLENE DIAMENE, POLYETHYLENE IMINES OF 1000-40,000 MOLECULAR WEIGHT AND DI(AMINOPOLYMETHYLENE) PIPERAZINE. THE SULFONAMIDES ARE CONVENIENTLY PREPARED AS SOLUTES IN LIGHT MINERAL OIL (WHITE OIL TO SAE 10 TYPE HYDROCARBON OIL) BY REACTION OF SUITABLE ALKYLBENZENE SULFONIC ACID CHLORIDE AND THE POLYMETHYLENE-CONTAINING DIPRIMARY AMINE IN THE PRESENCE OF PYRIDINE AND C5-C8 ALKANE, REMOVING THE ALKENE AND PYRIDINE, TREATING THE RESIDUE WITH A LIGHT MINERAL OIL SUSPENSION OF CALCIUM HYDROXIDE AND FILTERING THE RESULTING MIXTURE.

United States Patent 3,711,408 SULFONAMIDES OF HIGH MOLECULAR WEIGHT ALKYL-SUBSTITUTED BENZENE SULFONIC ACIDS AND THEIR PREPARATION Robert E. Karll, Munster, Ind., and Richard J. Lee, Park Forest, lll., assignors to Standard Oil Company, Chicago, Ill. No Drawing. Filed Apr. 1, 1970, Ser. No. 24,806 Int. Cl. Cm 1/36, 1/38 US. Cl. 252-475 7 Claims ABSTRACT OF THE DISCLOSURE Polymethylene-containing sulfonamides of alkyl substituted benzene sulfonic acids whose alkyl-substituent has a molecular weight in the range of 400 to 2800 are oil soluble, impart thermally stable dispersancy to oil solutions of the sulfonamides. The sulfonamides are preferably of polymethylene-containing diprimary amines su. h as polyazalkylene diamine, polymethylene diamine, polyethylene imines of WOO-40,000 molecular weight and di(aminopolymethylene) piperazine. The sulfonamides are conveniently prepared as solutes in light mineral oil (white oil to SAE 10 type hydrocarbon oil) by reaction of suitable alkylbenzene sulfonic acid chloride and the polymethylene-containing diprimary amine in the presence of pyridine and C -C alkane, removing the alkane and pyridine, treating the residue with a light mineral oil suspension of calcium hydroxide and filtering the resulting mixture.

BACKGROUND OF THE INVENTION sulfonamides are known to possess chemical and physical stability. sulfonamides of benzene and alkylbenzene sulfonic acids previously known, while soluble in hydrocarbon oils, have not had sufiicient oil solubility or stability to make them generally attractive as addition agents for lubricating oil formulations, especially as primary detergent or dispersant addition agents for said formulations. Rather the previously known sulfonamides have found some secondary use in lubricant formulations as anti-rust and anti-corrosion agents.

US. Pat. No. 2,660,562 discloses guanidine salts of alkyl, alkylaryl and petroleum sulfonic acids (mahogany acids) as gelling agents for grease preparation, anti-rust agents for oils and detergents for oils. For grease gelling agents the alkyl content of the sulfonic acid-guanidine salt should have 17-35 carbon atoms, for anti-rust agents have up to 40 carbon atoms and for detergency agents must have 40 to 70 carbon atoms. Thus for said detergency use of guanidine salt has in its alkylbenzene moiety an alkyl group of about 560980 molecular weight. Such guanidine salts were derived from guanidine, or its carbonate, methyl guanidine, monoand diphenyl guanidine, wax-alkyl-substituted guanidines, chloroguanidine, and phenyl biguanidine; by their reaction with the sulfonic acid having 4070 carbon atoms in their alkyl chain. Which such Cl -C alkyl containing salts had a sufficiently large alkyl group to impart suitable oil-solubility, the character and nature of the guanidine moiety were small when compared to the moiety contributed by the sulfonic acid. That patent establishes that such guanidine salts as acceptably useful lubricant oil detergents for the severity use required at the time (about 19505 1) that said invention was made. One basis for use acceptance was the diesel engine CRC L-l Test (using modified HZ-Lauson engine) in which an alkaline earth metal salt of alkylphenol sulfide would give a passing detergent rating. However, as time has gone by the in-service detergency requirments for diesel engine 3,711,408 Patented Jan. 16, 1973 crankcase lubricating oils have increased and said diesel engine L-l Test (rather low temperature severity) has been successively superseded by 1-D Test, then by 1- G Test and finally by Caterpillar-1H Test which is far more severe with respect to operating temperature and oil environment during the test. Oils containing said guanidine salts, While given a passing rating in the CRC- L1 Test would not pass the much more severe CaterpillarlH Test.

SUMMARY OF INVENTION We have discovered a novel class of lubricant oilsoluble alkylbenzene sulfonamides whose amide moiety with respect to the alkylbenzene sulfonic acid moiety is larger and different than the same relationship of guanidine moiety to alkylbenzenesulfonic acid in the prior guanidine salts. Hence the novel sulfonamides provide detergency-dispersancy properties in lubricating oils that advantageously meet more severe requirements of the diesel engine Caterpillar-1H Test. The novel sulfonamides have high molecular weight nuclear alkyl-substituent on the benzene ring. Preferably said nuclear alkyl-substituent has a molecular weight in the range of 400 to 2800 and most preferred of these are the nuclear polypropyl and polybutyl substituents of number average molecular weight (TL) in the range of 400-2800. The amide moiety of the sulfonamide is derived from polymethyl-containing two primary amine groups which include the types polymethylene diamine, polyazamethylene diamines, di (aminopolymethylene) piperazine and polyethylene imine T 600-40,000. Such novel sulfonamides are monoand disulfonamides having the formula:

wherein R is the alkyl substituent of 400-2800 M Y is the polymethylene containing moiety of the diprimaryamine .and Z is hydrogen (mono-sulfonamide) or (disulfonamide) wherein R is the 400-2800 M substituent.

This preparation of alkylbenzene sulfonamides by reaction of an amine with alkylbenzene sulfonic acid is somewhat unsatisfactory because amine salt formation is favored and substantial energy is required to convert the salt to amide through the removal of one oxygen atom from the sulfur atom.

We have found that the preparation of the present inventive alkylbenzene sulfonamide products can overcome those drawbacks by reacting alkylbenzene sulfonic acid chloride with the polymethylene containing diprimary amine in the presence of a C -C alkane reaction diluent and pyridine as hydrogen chloride acceptor, removing both alkane and pyridine by evaporation or distillation, treating the residue with a light oil (white oil to SAE 10 hydrocarbon oil) suspension of calcium hydroxide in an amount equivalent to the alkylbenzene sulfonic acid chloride, and then filtering the resulting mixture to remove calcium chloride. In this way alkylbenzene sulfonic acid chloride does not bring in unwanted impurities and byproduct water does not have to be driven off from a liquid product. Although pyridine is initially used as HCl acceptor, distillation or evaporation removal of pyridine does not remove by-product HCl. This by-product is removed as solid calcium chloride.

The monosulfonamide is obtained by using alkylbenzene sulfonic acid chloride and polymethylene-containing diprimary amine in the respective reactant molar ratio of 1.0: 1.0 and in the respective reactant molar ratio of 2.0: 1.0

for disulfonamide preparation. For each mole of alkylbenzene sulfonic acid chloride used there is produced 1.0 mole HCl. To convert HCl to CaCl there is used one equivalent (0.5 mole) of calcium hydroxide. Thus the amount of Ca(OH) used (0.5 to 1.0 mole) is equivalent to the 1.0 to 2.0 moles alkylbenzene sulfonic acid chloride, since 1.0 mole of Ca(OH) represents two equivalents with respect to 1.0 mole of HCl.

The alkylbenzene sulfonic acid chloride is conveniently obtained for said sulfonamide preparative method by ambient temperature (75-80 F.) sulfochlorination of the appropriate alkylbenzene by either of the following two reactions in the presence of C to C alkane for good physical contact of reactants. An equal molecular portion of sulfuryl chloride (SO CI and chlorosulfonic acid (CISOgH) is used as chlorosulfonation agent to chlorosulfonate and alkylbenzene. The chlorosulfonation reaction on alkyl benzene is carried outwith 1.0 mole of said chlorosulfonation agent per mole alkylbenzene. In place of said chlorosulfonation agent chlorosulfonic acid (ClSO H) can be used in the ratio of two moles thereof per mole of alkylbenzene, the sulfuric acid sludge, which then upon addition of water to 85-87% H 50 readily settles out of the quiescent mixture and is easily and completely removed. The alkane solution of reasonably pure alkylbenzene sulfonic acid chloride is then used for the sulfonamide preparation before described.

EMBODIMENTS OF INVENTION The alkylbenzene sulfonic acid chloride reactant has been before Well defined with respect to the size of its nuclear alkyl substituent. The alkyl substituent can be de rived from any appropriate source when preparing the alkylbenzene for use in chlorosulfonation. Thus the alkylbenzene can be obtained by alkylation of benzene with any suitable alcohol, olefin or alkyl halide whose hydrocarbon portion has the requisite 400-2800 molecular weight. Advantageously the hydrocarbon alkylating agent is a liquid viscous polypropene or polybutene of M 400-2800 obtained by A101 catalyzed polymerization respectively of propylene or butene such as isobutylene, butene-l, butene- 2 and mixtures thereof and mixtures of butane, butene-1, butene-2 and isobutylene with or without small amounts of butadiene present. Such liquid polypropene and polybutene and their preparation are well known.

The C -C alkane reaction diluent used in chlorosulfonation and in the sulfonamide preparation are the pentanes, hexanes, heptanes and octanes both normal and brached chain as well as mixtures of normal and branched chain isomers.

The polymethylene-containing diprimary amines include polymethylene diamines of 2 to 10 methylene groups such as ethylene diamine; 1,2- and 1,3-pr0pylene diamine; 1,2-, 1,3- and 1,4-butylene diamine; 1,2-, 1,3-, 1,4- and 1,5-pentylene diamines; 1,2- to 1,6-hexylene diamines;

1,2- to 1,7-heptylene diamines; 1,2- to 1,8-octylene diamines; 1,2- to 1,9-nonylene diamines and 1,2- to 1,10- decylene diamines and their branched isomers. Polyazamethylene diamines are polymethylene-containing diprimary amines and illustrative thereof are the alkylene polyamines; e.g. ethylene, propylene, butylene, etc. polyamines; obtained by reacting a C to C alkylene dichloride with ammonia. 0f the preferred alkylene polyamines (therefore also of the polyazamethylene diprimary amine) are ethylene polyamines: H N-(C H NH) -H wherein x is a number of from 2 to 10. The polyethylene imines of 600-40,000 M are a well known class of compounds and are a type of polymethylene-containing diprimary amine within the understanding of this invention. The remaining type of useful polymethylene-containing diprimary amines useful in-providing the amide moiety of the present inventive sulfonamide compounds are di(aminopolymethylene) piperazine whose aminopolymethylene groups are aminoethyl, aminopropyl, aminobutyl, aminopentyl, arninohexyl, aminoheptyl, aminooctyl, aminononyl and aminodecyl groups, that is H N--(CH groups wherein x is a number from 2 to 10.

The novel inventive sulfonamides and their preparation are further described and illustrated by the following examples.

EXAMPLE 1 There are combined and stirred in a reaction vessel having a reflux condenser 0.84 moles of alkylbenzene sulfonic acid chloride whose alkyl group has 400 M and 1000 milliliters of heptane until a solution forms. To the stirred solution is slowly added 0.84 mole tetraethylene pentamine admixed with 89 grams of pyridine to maintain a temperature of 200 F. maximum. Thereafter the mixture is heated to reflux temperature of heptane (about 208- 210 F.) for 20 minutes and then heptane and pyridine were distilled out of the reaction mixture. A slurry of 31 grams of calcium hydroxide in 730 grams of SAE 5W oil are added and the hot mixture is filtered to remove calcium chloride. The filtrate contains about 50 Weight percent of monosulfonamide shown below and about 4% nitrogen by weight. Said monosulfonamide has the formula where R is 400 Wi alkyl.

EXAMPLE 2 The process of Example 1 is repeated except that the alkylbenzenesulfonic acid chloride has as its alkyl-substituent a polypropyl group of 729 EL and the slurry of 31 grams calcium hydroxide had only 113 grams of SAE 5W oil. The filtrate is obtained at 210 F. and contains 80.6% monosulfonamide and 2.35% nitrogen on weight basis. The monosulfonamide has the formula wherein R is a polypropyl of 729 11,.

EXAMPLE 3 A sulfonamide is prepared by reacting 1 mole of alkylbenzcne sulfonic acid chloride (alkyl-substituent is fi 729 polypropyl group) dissolved in 500 grams of hexane with 0.015 mole of poly(ethyleneimine) of 20,000 fi in the presence of 200 cos. of pyridine at a temperature of 180 F. or hexane reflux. Following removal of hexane and pyridine by evaporation, the residue is treated with a slurry of 56 grams calcium oxide in 800 grams of SAE 5W oil with stirring at a temperature of 300 F. The hot mixture is filtered. The filtrate contains 50 weight percent of the resulting sulfonamide of poly(ethyleneimine) and has a nitrogen content of 4-5 percent by weight.

EXAMPLE 4 The preparative method of Example 2 is repeated except that pentaethylene hexamine is substituted for tetraethylene pentamine. The filtrate contains on a weight basis about monosulfonamide of the formula wherein R is polypropyl of 729 M and 2.7% nitrogen.

EXAMPLE 5 The preparative method of Example 2 is repeated using 1 mole of alkylbenzene sulfonic acid chloride (alkyl is 729 M polypropyl) dissolved in 800 grams hexane and 0.5 mole of poly(ethyleneimine) of 600 fi Following removal of hexane and pyridine, the residue is treated with a slurry of 56 grams calcium hydroxide in 600 ccs. SAE 5W oil with stirring at 300 F. The hot filtrate contains the alkyl(polypropyl 729 M substituted benzene sulfonamide of said 600 M,, poly(ethyleneimine) in a concentration of 48.5 weight percent -4% nitrogen.

EXAMPLE 6 The preparativemethod of Example 4 is repeated ex- 5 cept the mole ratio of alkyl(polypropyl of 729 fi ysubstituted benzene sulfonic acid chloride to pentaethylene hexamine is 2.0: 1.0. The hot filtrate contains on a weight basis 68% of the disulfonamide of the formula:

10 RS ot-un-wininnnwi sQ-R wherein each -R is polypropyl of 729 M and 2% nitrogen.

EXAMPLE 7 There is prepared the disulfonamide of the formula:

CHI -CH2 CHz-CH:

EXAMPLE 8 The preparative method of Example 7 is repeated using a 2.0: 1.0 mole of alkyl (polypropyl of 729 M -substituted benzene sulfonic acid chloride to pentaethylenehexamine. The slurry of calcium hydroxide is adjusted to provide 2.0 equivalents of calcium per 2.0 moles of alkylbenzene sulfonic acid and the SAE 5W oil is adjusted to provide a weight percent concentration of the disulfonamide of the formula:

wherein each R is 729 fi polypropyl. The hot filtrate contains 1.7% nitrogen by weight.

Two lubricant oil formulations are prepared for testing as crankcase lubricating oils using alkylbenzene sulfonamides of this invention to demonstrate their utility. These formulations and their ingredients on a volume basis are:

FORMULATION A Ingredient: Volume percent SAE 20 oil 60.3 SAE 40 oil 320 Oil solution from Example 2 4.5 Oil solution zinc dialkyldithiophosphate 0.7 Oil solution calcium alkylbenzene sulfonate 1.5 Pour point depressant 1.0

Total 100.0

FORMULATION B Ingredient: Volume percent SAE 5W oil 37.15 SAE 10 oil 47.00 Viscosity index improver 7.75 Oil solution of Example 8 5.00 7 Oil solution zinc dialkyldithiophosphate 1.10 Oil solution of calcium alkylbenzene sulfonate 2.00

Total 100.00

In each of Formulations A and B the zinc dialkyldithiophosphate has primary alkyl groups and the solution contains 40 weight percent of the zinc salt. Also the calcium sulfonate solution contains 40 weight percent of calcium salt.

Formulation A was tested as crankcase lubricating oil in a diesel engine operated under the standardized Caterpillar-1H Test conditions for 240 hours. Examination and evaluation of the pistons after said test showed top ring groove failing of 15%, second ring groove had trace of carbon, third and fourth ring grooves clean, first land had 5% light lacquer, second and third lands clean and a brown lacquer under crown deposit.

Formulation B was tested in a 289 cubic inch V-8 engine of Ford Motor Company under the standardized 289 Ford sequence V B Test operation conditions for 192 hours. Results of this test made after conducting said test and inspection of engine parts were:

Total varnish (basis 50=clean) 34.1 Oil pump relief valve (l0=clean) 9.8 Valve lifters sticking 0 Plugging of oil screen 0 Total sludge (basis 50=clean) 37.8 Oil rings plugging (50% acceptable) percent 2 Piston rings sticking 0 Blow-by average (ftfi/hr.) 152.8 Percent PVC plugging:

192 hours (at 4 inch Hg) percent 7.6

192 hours (at 18 inch Hg) do 25 What is claimed is:

1. A composition comprising a light hydrocarbon oil solution containing 40-80 weight percent of said composition of the sulfonamide of high molecular weight alkyl-substituted benzenesulfonic acid which sulfonamide has the formula:

wherein R is the alkyl-substituent and has a molecular weight in the range of 400 to 2800; Y is polymethylene having 2 to 10 methylene groups, polyethylene imine having M in the range of 600-40,000, polyazethylene having the formula or N,N'-di(polymethylene) piperazinyl whose polymethylene groups contain from 2 to 10 methylene units; and Z is hydrogen or the group in said formula.

2. The composition of claim 1 wherein R in the formula is p2ol36propyl or polybutyl having M in the range of 400 to 8 0.

3. The composition of claim 2 wherein Z in the formula is hydrogen.

4. The composition of claim 2 wherein Z is and said R is polypropyl or polybutyl of M 400 to 2800. 5. The composition of claim 2 wherein said formula Y is CHzCH2lT1 -CH2CH2 Z is hydrogen and R is polypropyl of 729 fi 6. The composition of claim 4 wherein said formula Y is polyazamethylene of the formula CHz-CH:

8 References Cited UNITED STATES PATENTS Dietrich 252-47 Aderson et al 252-32] Drummond et a1. 252-515 A Anderson 252-475 X Weber et a1 2 60-556 AR- Nel'son et a1 260-556 AR Lippincott et a1 252-56 R' Stuart et a1 252-52 R Drummond 252-515 A PATRICK P. GARVIN, Primary Examiner 15 W. H. CANNON, Assistant Examiner and both R groups are polypropyl of 729 fi US. Cl. X.R. 

